Application method for abradable material
AssigneeGeneral Electric Company
InventorMark D. Gorman
Life of this patent
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Abstract
A method for applying a highly porous alumina material that is useful in the hot section of a jet aircraft engine. In order to apply the porous alumina, an aluminum-based metal/alumina material known in the art is first placed onto an aircraft engine component substrate. The aluminum-based metal is then dissolved using a solution that will not affect the alumina or the underlying substrate. The alumina is then washed with deionized water and dried. The aircraft engine component may be first masked by applying a non-porous metal oxide material to the component or by oxidizing the surface of the component. The resulting alumina has a porosity in the range of about 20% to about 45%. The alumina has globular interconnected surface features in the range of about 0.5 μm to about 20 μm.
Claims15
A process for applying a ceramic wear coating material to an aircraft engine component comprising the steps of:
- providing an aircraft engine component, of which at least a portion comprises a metallic substrate material,
- masking a preselected portion of the metallic substrate material by heating the aircraft engine component to a preselected temperature in the range of about 1500° F. to about 2350° F. for a preselected period of time prior to applying the sacrificial ceramic layer, wherein said heating forms a metal oxide film of preselected desired thickness on the outer surface of the metallic substrate material;
- applying a sacrificial ceramic layer to a preselected portion of a surface of the metallic substrate material, wherein the sacrificial ceramic layer is selected from the group consisting of silica, quartz, mullite, silicate glass, fluorosilicate glass, fluoroborosilicate glass, alumninosilicate glass, calcium silicate glass, calcium aluminum silicate glass, calcium aluminum fluorosilicate glass, and combinations thereof;
- providing a reactive molten aluminum-based metal;
- contacting the applied sacrificial ceramic layer with the molten aluminum-based metal, wherein the reactive aluminum-based metal is at least about 300° C. above its melting point, but below the softening point of the sacrificial ceramic layer, whereby a composite layer comprising alumina and aluminum-based metal is formed by a reduction reaction of the molten aluminum-based metal and the sacrificial ceramic layer to form a composite layer comprising an alumina ceramic component and aluminum-based metal, as the sacrificial ceramic layer is at least partially reduced, whereby the aluminum-based metal/alumina composite layer is a near net shape of the sacrificial ceramic layer;
- and
- leaching out the aluminum-based metal from the layer of aluminum-based metal/alumina composite, while avoiding leaching out metallic substrate material from the aircraft engine component, leaving a porous alumina layer.
A process for applying a ceramic wear coating material to an aircraft engine component comprising the steps of:
- providing an aircraft engine component, of which at least a portion comprises a metallic substrate material;
- masking a preselected portion of the metallic substrate material by applying a layer of metal oxide to it prior to applying the sacrificial ceramic layer, said metal oxide being non-porous and non-reactive in the presence of an aluminum-based metal about 300° C. or higher above its melting point;
- applying a sacrificial ceramic layer to a preselected portion of a surface of the metallic substrate material, wherein the sacrificial ceramic layer is selected from the group consisting of silica quartz, mullite, silicate glass, fluorosilicate glass, fluoroborosilicate glass, aluminosilicate glass, calcium silicate glass, calcium aluminum silicate glass, calcium aluminum fluorosilicate glass, and combinations thereof;
- providing a reactive molten aluminum-based metal;
- contacting the applied sacrificial ceramic layer with the molten aluminum-based metal, wherein the reactive aluminum-based metal is at least about 300° C. above its melting point but below the softening point of the sacrificial ceramic layer, whereby a composite layer comprising alumina and aluminum-based metal is formed by a reduction reaction of the molten aluminum-based metal and the sacrificial ceramic layer to form a composite layer comprising an alumina ceramic component and aluminum-based metal, as the sacrificial ceramic layer is at least partially reduced, whereby the aluminum-based metal/alumina composite layer is a near net shape of the sacrificial ceramic layer;
- and
- leaching out the aluminum-based metal from the layer of aluminum-based metal/alumina composite, while avoiding leaching out metallic substrate material from the aircraft engine component, leaving a porous alumina layer.
Dependencies are inferred from the claim text.